This invention relates to security devices. It is common for the prongs of an electrical plug at the end of an electrical cord to be left exposed when not plugged into an electrical receptacle. There is often nothing to deter an unauthorized user or untrained user, such as a child, from plugging the electrical cord""s plug into an electrical receptacle and using the power tool or other electrical appliance to which the cord is attached. It is also common for the exposed prongs to become bent or even broken from being stepped on or from contact with other items in the course of storage or transit.
A security cap is provided for mounting onto the prongs of an electrical plug for safety and protection of the prongs. The security cap when in place deters use of the power tool or other electrical appliance to which the electrical plug is attached, and covers and protects the protruding prongs from damage.
The security cap for electrical plugs comprises:
a) a lock body adapted to fit over electrical prongs that protrude from the end of an electrical plug;
b) a prong retainer mounted in the lock body, the prong retainer adapted to retain a prong that protrudes from the end of an electrical plug until moved to a prong disengaging position;
c) a release member mounted in the lock body and conditionally moveable against the prong retainer such that sufficient movement of the release member against the prong retainer causes the prong retainer to move to a prong disengaging position;
d) a keyed mechanism mounted in the lock body engaged with the release member such that upon the keyed mechanism being unlocked the release member is sufficiently moveable against the prong retainer to move it to a prong disengaging position.
On typical North American 3-prong polarized plugs, the ground prong is cylindrical with a rounded tip, while the AC current prongs are substantially flat and have holes adjacent to their tips, allowing the prong retainer of the present invention to be effective by having a knob mounted on a flange of the prong retainer, the knob positioned on the flange such that the knob is pressed into a hole on the electrical prong upon the electrical prong being slid into position along the flange.
In a preferred embodiment of the security cap:
a) the release member comprises a release cam, the release member being rotatably mounted on a spine;
b) the keyed mechanism comprises a keyed cylinder than is rotatable within the lock body upon the key releasing the mechanism;
c) the prong retainer comprises a pair of knobs respectively mounted on a pair of flanges, each knob mounted in a position to engage a hole adjacent to the tip of an electrical plug prong that is inserted into the lock body.
Thus a security cap that is mounted on the prongs of an electrical plug can be released by turning the key in the keyed mechanism, which rotates the keyed cylinder, which rotates the release member, such as a cam, which flexes the flanges of the prong retainer outward, thereby removing the knobs from the respective holes adjacent to the tips of the AC current electrical plug prongs.